This invention is directed to a process and apparatus for making pant-like disposable absorbent garments with single-piece elastic side panels, and to absorbent articles so made. The process eliminates the extra cost and material required to make similar absorbent articles with multi-piece side panels, joined together with seams.
Disposable absorbent garments having a pant-like configuration are used for child training pants, adult incontinence garments, diapers, swimsuits and the like. Referring to FIG. 1, a prior art pant-like absorbent garment 2 includes a waste containment section (xe2x80x9cchassisxe2x80x9d) 4 and two side portions 6 and 8 defining a waist opening 10 and a pair of leg openings 12 and 14. The side panel 6 includes stretchable panels 18 and 20 joined together at seam 30. The side panel 8 includes stretchable panels 24 and 26 joined together at seam 32. Seams 30 and 32 extend longitudinally from the waist opening 10 to the leg openings 12 and 14 of the garment 2.
The waste containment section 4 includes front and back portions 5 and 7, and central (xe2x80x9ccrotchxe2x80x9d) region 15. Chassis 4 includes multiple layers (not shown) including, for instance, a liquid-permeable top layer, an absorbent core layer, and a liquid-impermeable outer cover layer 16 which faces away from the wearer. The waste containment section 4 also includes elasticized waist portions 22 on the front and back of the garment. The leg opening portions 12 and 14 also include elastic portions 46 which extend substantially around the portion of the leg openings defined by the waste containment section 4.
The disposable garment also includes leak guards in both leg openings, which help prevent lateral leakage of waste material through the leg openings. The leak guards have commonly been provided by elasticized flap portions 50 which are connected to the interior of the garment along the lower part of each leg opening. During use, the elasticized flap portions 50 fit snugly against the wearer and effectively block most spillage of waste material from the leg openings.
The use of stretchable side panels 6 and 8 having two or more parts per panel, joined at seams, results from a conventional manufacturing process. In the conventional process, the absorbent garments are initially manufactured as a single, flat piece which is then folded over and connected at the side seams 30 and 32. The disposable absorbent garment industry is cost-competitive, and the side seams represent material and processing which is not essential to the finished product. From a cost standpoint, there is a desire for an inexpensive process for manufacturing disposable absorbent garments having single-piece elastic side panels, thus eliminating the side seams.
The present invention is directed to a process and apparatus for making a disposable absorbent garment without the side seams, and to a product having seamless, single-piece elastic side panels. The terms xe2x80x9celasticxe2x80x9d and xe2x80x9cstretchablexe2x80x9d include any material which can be stretched, and which tends to return to its original shape when relaxed. The process includes the steps of preparing a waste containment section (also called a xe2x80x9cchassisxe2x80x9d) of the absorbent article using conventional techniques, and folding the chassis so that a front portion is superimposed on a back portion thereof. The term xe2x80x9cchassisxe2x80x9d essentially means the absorbent article without the side panels. The folded chassis is transported along a conveyor in a machine direction, with the unfinished edges of the chassis substantially aligned with the direction of movement.
As the chassis travels forward, single-piece side panels on both sides of the conveyor are aligned, treated with adhesive along two opposite edges, and partially folded. When the chassis passes the location where the side panels are being processed, the partially folded side panels are completely folded over the edges of the chassis, such that the adhesive binds the edges of the side panels to the overlapped edges of the chassis. A similar result may be achieved using thermal bonding, ultrasonic bonding, or another suitable bonding technique.
The apparatus of the invention includes a rotary cam device having four stations and an internal vacuum chamber. As the cam device rotates, side panels pass through each of the four stations. A first station picks up a properly oriented side panel using a vacuum plate. A second station applies adhesive to the side panel edges. A third station begins to fold the side panel, and a fourth station closes the side panel over the edges of the chassis. The peripheral speed of the cam device is the same as the linear speed of the chassis, and the peripheral distance between each of the four stations is the same as the linear distance between successive chassis on the conveyor. Two rotary cam devices, which are similar but move in opposite directions, are positioned on both sides of the conveyor so that both side panels can be applied in this fashion.
The product of the invention is an absorbent garment similar to the one described above, except that the stretchable side panels are each constructed of a single piece, and without side seams.
With the foregoing in mind, it is a feature and advantage of the invention to provide an inexpensive process for applying single-piece elastic side panels to disposable pant-like absorbent garments.
It is also a feature and advantage of the invention to provide a simple apparatus for accomplishing this result.
It is also a feature and advantage of the invention to provide a relatively inexpensive disposable absorbent article having single-piece side panels, a lower cost of production, and better appearance and fit than similar articles having multiple-piece side panels.